1. Field of the Invention
The present invention relates to the preparation of maleamic acid, and, more especially, to the preparation of maleamic acid by reacting maleic anhydride with ammonia under conditions of optimal contact surface area.
2. Description of the Prior Art
Maleamic acid is conventionally prepared by reacting maleic anhydride with ammonia. The maleic anhydride is employed either in a soluble state or in the vapor phase.
JP-74/35,325 more particularly describes such a process, carried out in an organic solvent medium at a temperature which ranges from room temperature to 100.degree. C. The ammonia is introduced in gaseous state within the solvent. A subsequent isolation stage provides the expected product.
Maleic anhydride, when heated to at least its vaporization temperature, namely, at least 215.degree. C., with gaseous ammonia, also produces maleamic acid. However, this reaction requires the presence of a catalyst. This may be, in particular, a mixture of V.sub.2 O.sub.5, P.sub.2 O.sub.5 and Al.sub.2 O.sub.3 (USSR 36,282).